[eluser]aquary[/eluser]
Josepzin, in your case, it's not about CI protect the "nexts" string, but because it IS a string. You'll need to put it in a string anyway.
Also, try switching the condition of joining. I cannot remember why but I did got some problem like that before, somehow, I realized that I have to put the "relation" part (catalogs_arranges.catalog_id=catalogs.id) before the "condition" part (catalogs_arranges.key="nexts").....
Although "join" could be replaced with "where", the usage are not the same :3.